


Dude. That's Your Sister.

by Katieykat513



Category: Miraculous Ladybug
Genre: Crack, F/M, Incest, Pure Crack, but not really
Language: English
Status: Completed
Published: 2020-11-28
Updated: 2020-11-28
Packaged: 2021-03-09 20:20:23
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,700
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27752197
Author URL: https://archiveofourown.org/users/Katieykat513/pseuds/Katieykat513
Summary: Adrien likes to over think things, so when he is confronted with his feelings for Marinette at the exact same time he is adopted by the Dupain-Cheng family...what's a teenager to do when he is in love with his sister? Probably blurt out the wrong thing to the right person...
Relationships: Adrien Agreste | Chat Noir/Marinette Dupain-Cheng | Ladybug
Comments: 42
Kudos: 147





	Dude. That's Your Sister.

**Author's Note:**

> Well this is what happens when writers with spicy minds get together in one place....crack. Pure, uncut crack. XD 
> 
> I honestly don't remember who all was involved but I blame ghostlyhamburger, yamina, and talik. The others were probably there too...but the main offenders were them XD
> 
> So enjoy this mild story about a boy who gets adopted into a loving family. 
> 
> Thanks for the title talik XD

Adrien watched Marinette as she cut the cookies to prepare them for the oven. It had been a strange few months. His father had upset him, and Marinette had dragged him home where he ended up confiding in Tom about his troubles. It had felt amazing to be able to have the support of an adult male for once, instead of ridicule. 

He came over to the bakery so often the first few weeks that he started to hang out with Marinette more, and he started to notice her...a lot. But she was just a friend. Then fast forward to finding out that his father was Hawkmoth. Gabriel decided that leaving his son was better than being captured and placed in jail. Tom and Sabine had immediately stepped up and fostered him and were still going through the process of legally adopting him. 

He would forever be thankful to the Dupain-Chengs. Without Tom’s guidance the weeks leading up to the reveal, he probably would have been devastated by the fact that his father was his arch enemy...but in a way he was always his enemy. His enemy he tried to please at every whim. 

That had been a month ago. 

“You know you can put them in the oven instead of sitting there like a bump on a log.” A voice interrupted his thoughts. 

He looked up startled at Marinette, who was looking at him while hunched over a cookie sheet, cutting more cookies out. He hopped off the stool he sat on, “Oh right! Sorry!” He blushed. He walked over to the table and grabbed the tray and placed it into the giant oven. 

“You seem distracted, Adrien. What’s wrong?” She frowned at him.

“Uhh. It’s nothing. Really. I’m fine.” He rubbed the back of his neck and walked back over to his stool. He felt a hand on his shoulder.

“Adrien.” She began softly. “Is it...your father? I’m sure Ladybug and Chat Noir are doing their best to find him. At least they know who to look for now.” She said comfortingly. 

Adrien half grinned and asked. “What’s the matter with Papa?” 

Marinette scrunched her nose. “Oh! I forgot! You call Papa...Papa. Right. I meant Gabriel. Sorry.” She looked down at her hands, her face red with embarrassment. 

Adrien grinned at Marinette. Ever since Tom had taken him under his giant arm, Adrien had called Tom, Papa. And it felt amazing. Sabine even asked him to call him Mama, but he still loved his mother dearly, so he chose to call her Mama Sabine instead, which she was fine with. 

“No. I wasn’t thinking about him. I don’t waste brain cells on him. It was nothing really.” He reassured her. She looked at him suspiciously when her dad burst into the room.

“There is my lovely daughter and son! How are my two cinnamon rolls doing today!” Tom exclaimed as he scooped both Marinette and Adrien into a crushing hug.

Adrien returned the hug like always but his mind was miles away.  _ Daughter? Son? Does he see us both as his children? If that’s the case...then… _

He looked over at Marinette who was trying to squirm away from Tom and giggling.  _ She looks amazing when she laughs with her whole being. _ Adrien shook the thoughts from his head and engaged in a conversation with his Papa and...sister?

***********

A few weeks later they had finally gotten news that the adoption had gone through, accelerated by the circumstances surrounding the situation. The whole family had an extravagant dinner -they would later celebrate with friends and extended family that weekend- but for now it was just the four of them. 

Tom made a huge cake and as they were cutting into it he made an offhand comment about how Marinette and Adrien were no longer only children. Which was true. Adrien and Marinette were legally siblings now. 

Adrien had a faraway look as he took the plate handed to him.  _ Is this wrong to feel upset about that? I love having Tom and Sabine….but...a sister? _

They continued their celebration until it was time for bed, but for Adrien, it was time for patrol with Ladybug. 

He met up with Ladybug, sat down next to her, and handed her the cup of hot tea he picked up on the way there. They sat in silence as Chat got lost in his head again about Marinette and the adoption. 

There was an incident a few days before, where Marinette had fallen into Adrien’s space and they stared into each other’s eyes, lost in the moment. He had not realized at the time but he saw her lean forward and immediately claimed her lips in his. He devoured her with his lips as his hand gripped the back of her neck attempting to bring her closer. 

When they broke apart, nothing was said about the incident and they ended up going about their day as if nothing had happened. But every time that he saw her, his heart fluttered. Then they were swept up into the excitement of the adoption and it seemed like she did not wish to speak about it so he did not bring it up. 

_ Why does it feel so disappointing to have a sister? Is it because of how she looks at me? She always blushes when she looks at me. I know it’s not pity, what could be the issue?  _ He took a sip of his tea as his thoughts attempted to make sense of one another.  _ Why would she kiss me like that? Is that how brothers and sisters kiss? I’ve never had a sibling, maybe that’s just how it is? Why is it that my heart flutters every time that I am around her? Is this normal? _ All the adoption excitement was starting to get to him. 

He was so lost in his thoughts that he did not realize he voiced his next question out loud, “Am I in love with my sister?” Until the entire left side of his face was covered in tea after it was ejected from Ladybug’s mouth. He looked alarmed at Ladybug. “My lady, what’s wrong?! Is it the wrong order!?” He scrambled and stuttered, trying to figure out what was wrong.

Ladybug sputtered and coughed as she regained somewhat normal breathing. “I’m sorry...but...WHAT?!” She yelled the last part.

“What, what?” Chat answered.

“That!” She gestured to himself. “What you just said! About your sister!” 

Chat seized up, “Oh no. What did I say out loud?” He asked worriedly, ignoring the facts that the side of his face was soaked and sticky. 

“Um.” Ladybug started to say, but seemed unsure.

“What? Come on, please tell me! My mind is in a weird place right now!” He pleaded.

“Well that’s the thing, Chat. I think your weird thoughts came out, because you said...well. You said you were in love with your...sister…” 

There was a long awkward pause between the heroes. Chat’s face began to grow red the longer the silence lasted. 

“Just...kill me, please.” Chat hung his head and threw his hands over his face. “That came out without context and I am so, so sorry, my lady!” 

Ladybug grimaced and reached up to bring his hands away from his glowing face. “Well. How about you give me the context. So I don’t think the worst, hmm?” 

Chat took a deep breath and sighed. “Well it’s a weird situation...I guess? You see. I was adopted today.” 

He felt Ladybug freeze before she grabbed his face, looking into his eyes. “A-a-adopted?? But...I knew...I thought…your home life was not so nice...but oh my god, Chaton! I didn’t know you were an orphan!!” She exclaimed, clearly thinking that Chat had no one to care for him except those at an orphanage. 

Chat smiled and brought his hands up to bring Ladybug’s away. “Well, I wasn’t always. It was for only a few months. But, the family who took me in when my father was...arrested, lets say, is actually one I have known for a few years.” He looked down at their joined hands. “My papa. He’s the nicest man in the whole world.” Ladybug felt a twinge at the familiar tone of voice used when he said papa. “And his wife is probably one of the kindest women I have ever met, next to my own mother.”

Ladybug had tears in the corners of her eyes listening to Chat. His emotion as he spoke about his family was sad and beautiful at the same time. 

“Oh, my lady! Don’t cry!”

“Sorry. Just got a little emotional. So, what’s this bizarre situation with your sister?” Ladybug sniffled.

Chat blushed again. “Right. Uh. Well you see. The couple who adopted me...they have a daughter.” He let go of Ladybug’s hands and rubbed the back of his neck with one hand, the motion familiar to Ladybug but she could not quite place it. “And I swear! My lady, I have always been in love with you! But lately...I don’t know...it’s just...I’m so confused!” He threaded his claws in his hair and let out a disgruntled huff. “She’s always been just a friend!  _ Just _ a friend!” He reiterated the phrase, which was enough to cause Ladybug to freeze and go white. 

“No.” She whispered, although he heard her.

“Yes!” He responded back. He started to pace. “And it’s not like she’s my blood sister, but her father calls us his children and we sleep in the same house and eat at the same table and we share the same bathroom!” He continued to ramble as Ladybug tried to catch his attention. “I almost saw her naked the other week! In her room!” He yelled in Ladybug’s direction. “I had to quietly back away as she lowered the towel, but I definitely saw the top of her butt and holy crap I had to go back to my room and...nevermind!” 

“Chat.” Her face glowed red.

“And then after I got done, I thought, am I wrong? Is this whole situation weird!? Why would I be getting boners for my friend?”

“Chat.”

“I mean sure, I’m seventeen and she's ridiculously cute, but...now she’s legally my sister! Do you know how weird that is! ?To think those things about your sister! What would Papa say!” He placed his hands on his cheeks, stretching his mouth open wide, gasped. “They’re going to send me to pervert jail or something! For impure thoughts!” 

“Chat!” She tried a little louder, trying not to freak out too bad.

“Gaahhh! Why did I have to fall in love with my sister!!” He screamed.

“Uhg. Adrien!” Ladybug yelled louder, her face still red from his confession. 

Chat froze as he looked at Ladybug in shock. “How...who...what? I’m not...who’s Adrien?” He tried to divert.

Ladybug smiled and shook her head. “You’re silly.” She booped him on his nose and smiled. “Why don’t you just tell her the truth instead of making it weird?” 

“Because then that would be weird!! And they’ll kick me out! They’ll send me back to live with  _ him _ ! I can’t! I can’t go back to that! I won’t!” Chat shook his head vigorously while his hands were clutched at his sides.

Ladybug grabbed his shaking head and forced him to look in her eyes. “Listen here, silly boy.” He nodded his head, his cheeks squished between her hands. “What if...your sister was in love with her brother? Would it still be weird?” She inquired.

“What no! She’s not in love with her brother! She’s told me many times she wasn’t in love with me! I’ve asked her...twice!” He yelled through his pursed lips.

She released one of his cheeks and slapped his face lightly, squishing the cheek again. “Stop being dumb.”

“Huh?”

“You are being an absolute adorable dork about this whole thing. And you have unknowingly given away your secret identity, Adrien. So you are going to listen to me, and listen to me well.”

He nodded his head.

“Good. You are going to go home right now.” He nodded. “You are going to go up to Marinette.” Another nod. “Grab her by the face exactly like I have you now.” He nodded harder and looked deep into her eyes. “And...ah the heck with it!” 

She pulled Chat’s face down to hers and crashed her lips to his, claiming them as hers momentarily before pulling back with a large breath. Chat was speechless as he stared wide eyed at Ladybug. “Wh-wh-what was...was that?”

Ladybug giggled before bringing him back down to her face. She rubbed her nose against his. “Oh. You know. Just a really  _ incestuous _ kiss between brother and sister.” She joked.

Realization flashed through Chat’s eyes. He brought his hands up to her face as she had instructed him to previously. “Oh. I feel kind of dumb now.” 

Ladybug grinned. “I bet you do. It’s ok. I feel dumb too.”

He chuckled and brought her face up to his as he claimed her lips this time. He angled his and her heads just right so they could kiss without the squishing of noses, heavy breathing mingled between them so they did not have to come up for air. The passionate kiss became small pecks as they finally pulled away from each other.

“Adrien.” Ladybug whispered against Chat’s lips before pecking them again.

“Yes, my lady?” He whispered back, capturing her lips briefly again. 

“Wanna be the Jaime to my Cersei?” She grinned against his lips as he froze in confusion.

“Wait. What?”

A wicked grin spread across Ladybug’s face but Chat reached down and captured her lips before she could utter another word. 

“I don’t even want an answer to my question because now I am sure you are making fun of me, but know that you are no Cersei Lannister.” 

She giggled and threw herself around his shoulders in a hug as his arms came to squeeze her around the waist. “You were the one freaking out, chaton. Making up silly things in your head. Being adopted just means that the city can’t take you away from us. You belong to us, forever! Now come on! Let’s go home. I am sure Mama and Papa are dying to settle their bet.”

Chat pushed her away from him confused. “Their bet? What bet?” He cocked his head to the side.

Ladybug backed fully out of his arms and reached for her yo-yo, angling herself towards home. “Yes. They have had a bet going ever since I was fourteen. When you would notice me or when I would work up the nerve to ask you out. That kind of stuff.” 

She looked back to see Chat with his body sagged forward and his mouth hung open. “How have I never known?” He whispered.

“Well, to be honest, you are kind of dense.”

“Hey!” He interrupted. She held out her hand to silence him.

“And I am a coward who can’t admit to the boy she likes that she likes him. And instead lied to him. So we are both at fault here, yes?”

Chat nodded his head. “Yes.”

“Alright then.” She placed her hands on her hips and stood with pride. “Now come on. Let’s go home. I want to do inappropriate things with my brother.” She grinned at him.

Chat calculated her command before opening his mouth in shocked realization. “What?! No! That’s not what...I didn’t mean…I mean... no!” He shook his head to clear it. “How dare you twist a man’s words when he is in a state of panic!” He playfully accused.

“Your words, not mine.” She shrugged and leapt to the next roof. “Catch me if you can, oniisan!!!” She pitched her voice higher, poking fun at his choice in entertainment. 

“Don’t you ‘oniisan’ me! Get back here!” He yelled into the night, jumping after her. 

The only thing heard over the rooftops that night was the insane gigglings of two teenagers and jabs about incest...and it surprisingly never made it to the Ladyblog.


End file.
